SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b7b98295635f7b878384a98018ae4fd8fa90c39875151caa517f56f7707792a' 
  AND token = 'l4WZN1H3r82Pu6q4kugPkMbz81j1Obx10+QBG1tWZTo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}